This invention relates to a process for the manufacture of a solenoid operated valve, particularly a solenoid operated valve of the double seat type having valve seats at spaced symmetric positions.
A solenoid operated valve of the double seat type includes first and second valve seat members abutted at mutual joining surfaces, and a ball valve disposed in a valve housing chamber defined between the two seat members. The ball valve is seatable alternately on the two valve seats, as disclosed in Japanese Patent Publication No. 49-10371. In forming a solenoid operated valve of this type, it is not possible to obtain correct accuracy only by cutting operations of the valve seat members, since the distance of shaft of the ball valve between the double valve seats is very small, namely, 10.sup.-1 mm.
For this reason, in the conventional manufacturing technique, when the valve seat members are assembled, a spacer is interposed between the joined surfaces thereof, and the distance between the two seats is adjusted to control the amount of lift of the ball member by adjustment of the thickness of the spacer. Thereafter, the valve seat members are assembled to obtain a correct lift amount. The adjustment of the amount of lift at the time of assembly particularly is extremely difficult as the amount of lift is 10.sup.-1 mm, and many hours are required for manufacture.